UV ABSORPTION CROSS-SECTIONS FOR SO3

Room temperature gas phase absorption cross sections for SO, have been measured over the wavelength range 195 to 330 nm using a diode array spectrometer. The SO, spectrum is continuous with weak diffuse vibrati onal band structure in the 225 to 295 nm region. Atmospheric photolysi s rate calculations show that photolysis of SO, in the 190 to 230 nm a ctinic window is important in determining the sulfur partitioning in t he upper stratosphere.